by Michael Winter, USA TODAY

by Michael Winter, USA TODAY

Under the measure that passed the Democratic-controlled chamber on a 34-21 vote, the definition of marriage would change from an act between a man and a woman to two people.

The measure, SB 10, provides that all state laws covering marriage "apply equally to marriages of same-sex and different-sex couples and their children."

Churches and other religious organization cannot be required to "solemnize" same-sex marriages, and churches cannot be sued for refusing to allow such ceremonies in their sanctuaries, which the measure says is protected under the First Amendment of the U.S. Constitution.

The legislation heads the House, where Democrats also have a majority. Gov. Pat Quinn, also a Democrat, has said he would sign the bill if it reaches his desk.

Sen. Heather Steans, a Chicago Democrat who sponsored the measure, said was time for Illinois to eliminate the "second-class status" of gay and lesbian couples.

Only one Republican voted yes.

"I think it was the right thing to do," said Sen. Jason Barickman, from Champaign, according to the Associated Press. "It's a vote that I understand some have varying opinions on, but I feel that I voted in the correct way."

If the bill becomes law, Illinois would be the 10th state to allow same-sex couples to wed.